Page 1 of 6

This working document was prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions with the

ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or ABRWH (or their technical

support and review contractors) positions unless specifically marked as such. This document represents preliminary positions taken on technical issues prepared

by NIOSH or its contractor. NOTICE: This document has been reviewed to identify and redact any information that is protected by the Privacy Act 5 USC

§552a and has been cleared for distribution. 

DEPARTMENT OF HEALTH & HUMAN SERVICES 

National Institute for Occupational Safety and Health 

 Division of Compensation Analysis and Support 

Memorandum

To: Carborundum Work Group 

From: Thomas P. Tomes, DCAS Health Physicist 

Subject: Use of Surrogate Data at the Carborundum Company

Date: 10/27/2016 

The DCAS assessment of doses to workers at the Carborundum Company in the Evaluation Report (ER) 

for petition SEC-00223 included the use of data from Battelle-TBD-6000 (Battelle, 2011) to estimate 

internal and external doses to workers at Carborundum. This correspondence evaluates the applicability 

of the surrogate data in TBD-6000 against the criteria established by DCAS in OCAS-IG-004 (DCAS, 

2008). The Advisory Board has a document with similar criteria for use of surrogate data (ABRWH, 

2010). 

The Carborundum Company in Buffalo, NY, is a covered AWE facility in June through September 

1943, and from 1959 through 1967. The 1943 work was limited to the experimental grinding of 

uranium metal slugs. The 1959 through 1967 work involved developmental research, fabrication and 

study of the properties of refractory uranium compounds and mixed plutonium/uranium compounds. In 

addition to the developmental work, the compounds were synthesized into small pellets for fuel for 

experimental testing in a reactor (at another site). 

The DCAS ER relies on surrogate data contained in TBD-6000 to estimate external and internal doses 

for the 1943 experimental work with uranium metal. It also relies on surrogate data for the 

reconstruction of external dose from uranium work in 1959 through 1967. External dose from the mixed 

uranium/plutonium compounds do not rely on surrogate data, nor do estimates of intakes for 1959 

through 1967. 

1943 Work 

As described in the ER, the 1943 work was limited to experimental centerless grinding of ten uranium 

slugs for the purpose of selecting an abrasive that could be used (by others) to finish grind uranium 

metal. Ten slugs totaling 30 pounds were used in the testing. 
Use of Surrogate Data at the Carborundum Company 

Page 2 of 6

This working document was prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions with the

ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or ABRWH (or their technical

support and review contractors) positions unless specifically marked as such. This document represents preliminary positions taken on technical issues prepared

by NIOSH or its contractor. NOTICE: This document has been reviewed to identify and redact any information that is protected by the Privacy Act 5 USC

§552a and has been cleared for distribution. 

There are no personal or area monitoring data, and none are known to exist, to estimate radiation doses. 

The source term for exposure is known: thirty pounds of natural uranium metal slugs. The ER refers to 

doses provided in Site Profiles for Atomic Weapons Employers that Worked Uranium Metals, BattelleTBD-6000, as an appropriate surrogate. Although TBD-6000 was developed for the reconstruction of 

doses at AWE facilities in the absence of monitoring data, its applicability must be established on a case 

by case basis. 

Implementation Guide 004 (IG-004) has a list of criteria that must be meet for the use of surrogate data 

when the hierarchy of data indicates surrogate data can be considered. Each of the five criteria discussed 

in IG-004 were evaluated for the applicability of the data in TBD-6000 to the reconstruction of doses 

during the grinding of slugs in 1943. 

Source Term 

As provided in the ER section 5.1.1, the source term for the 1943 work at Carborundum is well known. 

The work was limited to natural uranium metal slugs, which is included in the various shapes of metal 

evaluated TBD-6000. The source terms are similar. 

Facility and Process Similarities 

Carborundum’s 1943 work did not involve a production process, but they handled a few uranium metal 

slugs and experimented with different abrasives and machine settings with a centerless grinder. TBD6000 external doses include specific evaluations of exposure to workers handling uranium metal, 

including slugs; it also includes estimates of airborne radioactivity and intakes by workers involved with 

the centerless grinding of uranium metal. The Carborundum centerless grinding was limited to a short 

period of time, but involved some repeated grinding of the same pieces. One of the considerations in IG004 is size and ventilation of the work area, which is unknown at Carborundum for the 1943 work. 

The values for centerless grinding in TBD-6000 are those reported for unventilated grinding, which very 

likely was the case for Carborundum in 1943. The 1943 work was not a production operation as 

compared to TBD-6000, yet could have had intermittent high concentration around the machine. Based 

on the operations described in the report from Carborundum, testing was done in June 1943 during 

which they made frequent changes of wheels and machine settings until they found an abrasive that 

worked. Once an effective abrasive and machine settings were determined experimentally, they ground 

the slugs on a number of passes. That was the extent of the work. The TBD-6000 centerless grinding 

intake rate is the daily weighted average for a centerless grinder operator in a facility that had no 

ventilation to mitigate airborne releases into the breathing zone of the operator. Those operators were 

exposed to very high airborne concentrations, with the average daily exposures provided in TBD-6000. 

The next section discusses the underlying data in TBD-6000 in more detail. 
Use of Surrogate Data at the Carborundum Company 

Page 3 of 6

This working document was prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions with the

ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or ABRWH (or their technical

support and review contractors) positions unless specifically marked as such. This document represents preliminary positions taken on technical issues prepared

by NIOSH or its contractor. NOTICE: This document has been reviewed to identify and redact any information that is protected by the Privacy Act 5 USC

§552a and has been cleared for distribution. 

Temporal Considerations 

Building design and process changes are identified as issues that could impact intakes of workers doing 

the same work, but in facilities designed in different eras. There is no definitive information on design of 

the grinding operation at Carborundum, and efforts to obtain more information were unsuccessful. There 

is no reason to think any special engineered controls were in place at Carborundum. The bounding 

intakes for a centerless grinder operator at Carborundum is based on uranium air concentration released 

from the grinder into the breathing zone of the machine operator, which is the specific exposure scenario 

for centerless grinding evaluated by Harris and Kingsley (1959), the main reference for intakes in TBD6000. Harris and Kingsley evaluated operators who were exposed to centerless grinding of uranium 

metal slugs in both unventilated and ventilated operations, providing maximum observed concentrations 

released into the breathing zone of an operator. They also provided average daily weighted air 

concentrations for facilities without designed controls and for those with ventilation on the grinder in the 

1950s. The average daily air concentration for unventilated work is provided in TBD-6000. The average 

daily intakes from ventilated grinding are much lower than the intake rates provided in TBD-6000. The 

higher air concentration in TBD-6000 for unventilated exposure is appropriate for Carborundum. 

SC&A also evaluated the intakes specified by NIOSH for Carborundum and concluded it was 

sufficiently bounding and allows for the maximum observed (by Harris and Kingsley) air concentration 

released into the breathing zone of an operator (SC&A, 2016, section 5.2.1). 

Data Evaluation 

The quality of the TBD-6000 data and the applied uncertainty has been reviewed previously by NIOSH 

and the Advisory Board. Therefore, it is not necessary to review the quality and validity of the TBD6000 data. 

Review of Bounding Exposure Models 

The plausibility of intakes at the levels provided in TBD-6000 was considered. The Carborundum work 

with uranium in 1943 was not a production operation, although the work could have had significant 

grinding for short periods of time. Carborundum reported the results of the experiments one month after 

receipt of the ten uranium slugs. However, the slugs were on site for about four months total. Although 

the intake value from TBD-6000 is appropriate for centerless grinding, it may be high based solely on 

quantity of materials in process at Carborundum. Carborundum experimented with the same slugs using 

different abrasives and machine settings. Once an effective abrasive and machine settings were 

determined experimentally, they ground the slugs on a number of passes. Based on the amount of work 

performed, the centerless grinder operator was likely exposed for a significant amount of time for a 

relatively short period. NIOSH currently has no definitive information to adjust the number of hours 

exposed to allow for the actual time uranium was ground during the four months in 1943. Therefore, the 
Use of Surrogate Data at the Carborundum Company 

Page 4 of 6

This working document was prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions with the

ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or ABRWH (or their technical

support and review contractors) positions unless specifically marked as such. This document represents preliminary positions taken on technical issues prepared

by NIOSH or its contractor. NOTICE: This document has been reviewed to identify and redact any information that is protected by the Privacy Act 5 USC

§552a and has been cleared for distribution. 

doses and intakes from TBD-6000 for the period “up to 12/31/1950” are applied for the four month 

AWE period. Those are considered plausible bounding dose rates. 

1959 through 1967 Work 

The ER relies on surrogate data for external dose estimates for workers exposed to uranium during 

developmental research, fabrication and study of the properties of refractory uranium compounds. 

NIOSH does not use surrogate data to estimate external dose for exposure to mixed uranium/plutonium 

carbide, nor is surrogate data used for internal dose estimates for the 1959 through 1967 period. 

There are no available dosimeter data or area monitoring data. Efforts to locate data were unsuccessful. 

The source term for uranium exposure are the uranium compounds: uranium nitride (UN), uranium 

carbide (UC), and uranium silicide (U3Si2), and the source compounds used to synthesize them. The ER 

Table 5-2 entries for contract AT-(40-1)-2558 identifies the source uranium compounds used: UO2, 

U3O8, and uranium shot. That table also provides the SRDB Ref ID numbers for various reports 

describing the processes and work with uranium. 

The ER uses external doses provided in Site Profiles for Atomic Weapons Employers that Worked 

Uranium Metals, Battelle-TBD-6000. That has been used by NIOSH as surrogate data for work at other 

uranium processing facilities. 

IG-004 has a list of criteria to be met for surrogate data use when the hierarchy of data indicates 

surrogate data can be considered; each criteria is discussed below. 

Source Term 

Records indicate the uranium work under contract AT-(40-1)-2558 involved normal and depleted 

uranium. TBD-6000 provides dose rates for exposure to uranium metal, and has a table of beta dose 

rates from various uranium compounds and natural uranium metal. UO2 and U3O8 are listed and are 

marginally lower than dose from metal. The refractory compounds synthesized at Carborundum (noted 

above) are not listed in the table, but those compounds should also be marginally lower than the more 

dense uranium metal. Records indicate some limited work with other uranium compounds as well, such 

as ammonium diuranate. Therefore, the dose rates from uranium metal should provide a sufficient and 

favorable estimate of dose rates from the compounds produced at Carborundum. 

Facility and Process Similarities 

The design of the facility and details of the processes at Carborundum have limited impact on estimates 

of the external doses provided in TBD-6000. The TBD-6000 bounding doses to an operator are based 

on the assumption an operator spent 50% of the workday at a distance of 1 foot from the surface of 
Use of Surrogate Data at the Carborundum Company 

Page 5 of 6

This working document was prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions with the

ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or ABRWH (or their technical

support and review contractors) positions unless specifically marked as such. This document represents preliminary positions taken on technical issues prepared

by NIOSH or its contractor. NOTICE: This document has been reviewed to identify and redact any information that is protected by the Privacy Act 5 USC

§552a and has been cleared for distribution. 

uranium metal. So, the principle issue is the assumption of number of workhours a Carborundum 

worker spent in close proximity to the pieces of uranium being fabricated. 

That time of exposure appears sufficient for Carborundum given the various steps involved in 

synthesizing and studying the materials. That work included small batch processing of the source 

uranium in the laboratory equipped with gloveboxes, grinding mills, and furnaces. Batch work included 

holding times in mills and furnaces (many hours) in the preparation of the compounds and pressing them 

into shapes for testing and sintering. Small pellets and a couple other shaped pieces were made for 

different physical examination and testing of the pieces (AEC, 1961). 

From a review of the various project progress reports, it appears that, on average, a significant amount of 

time would have been spent away from direct contact with the materials. Given that NIOSH has no 

personal dosimeters for those workers, the assumption of a one foot distance exposure 50% of the time, 

as provided for uranium metal in TBD-6000 should provide a favorable bounding dose rate. 

Temporal Considerations 

The methods of external dose modeling do not rely on changes to facilities from one era to another. The 

Carborundum uranium work was experimental laboratory scale developmental work with limited 

production of product. The discussion in the Facility and Process Similarities section above regarding 

time and distance is the primary issue in use of the surrogate data. 

Data Evaluation 

The quality of the TBD-6000 data and the applied uncertainty has been reviewed previously by NIOSH 

and the Board. Therefore, it is not necessary to review the quality and validity of the TBD-6000 data. 

Review of Bounding Exposure Models 

The dose rates in TBD-6000 are considered reasonable estimates for the uranium compounds and pieces 

of uranium refractory compounds synthesized at Carborundum. The 50% workday exposure model at 

one foot is a reasonable bounding estimate. 

Conclusion 

NIOSH reviewed the use of surrogate data in the reconstruction of doses for workers at the 

Carborundum Company against the criteria contained in OCAS-IG-004. Based on the evaluation 

provided above, NIOSH concludes that the use of surrogate data in TBD-6000 is appropriate for 

bounding: 1) internal and external exposure to uranium in 1943; and 2) external exposure to uranium 

compounds from 1959 to 1967. 
Use of Surrogate Data at the Carborundum Company 

Page 6 of 6

This working document was prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions with the

ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or ABRWH (or their technical

support and review contractors) positions unless specifically marked as such. This document represents preliminary positions taken on technical issues prepared

by NIOSH or its contractor. NOTICE: This document has been reviewed to identify and redact any information that is protected by the Privacy Act 5 USC

§552a and has been cleared for distribution. 

References 

ABRWH, 2010, Final Draft Criteria for the Use of Surrogate Data, National Institute for Occupational 

Safety and Health, Advisory Board on Radiation and Worker Health, May 14, 2010, 

http://www.cdc.gov/niosh/ocas/pdfs/abrwh/proc/abrwh-proc-sd-r0.pdf

AEC, 1961, K. M. Taylor and C. H. McMurtry, Research and Development Division, Carborundum 

Company, Synthesis and Fabrication of Refractory Uranium Compounds, Summary Report May 1959 

Through December 1960, ORO-400, Atomic Energy Commission Office of Technical Information, 

February 1961, SRDB Ref ID 140519. 

Battelle, 2011, Battelle-TBD-6000, Site Profiles for Atomic Weapons Employers that Worked Uranium 

Metals, Rev. 1; Division of Compensation Analysis and Support; effective June 17, 2011; SRDB Ref 

ID: 101251 

DCAS, 2008, OCAS-IG-004, The Use of Data from Other Facilities in the Completion of Dose 

Reconstructions Under the Energy Employees Occupational Illness Compensation Program Act, Rev. 0; 

Division of Compensation Analysis and Support; effective August 21, 2008. 

Harris and Kingsley, 1959, W. B. Harris and I. Kingsley, The Industrial Hygiene of Uranium 

Fabrication, A.M.A. Archives of Industrial Health, Vol. 19, pp. 76-101, May 1959. 

SC&A, 2016, S. Cohen & Associates (SC&A), Review of the Carborundum Special Exposure Cohort 

(SEC) Petition-00223 and the NIOSH SEC Petition Evaluation Report, SC&A-TR-SEC-2016-0001, 

Revision 1, January 27, 2016.